     (flush-batch update-batch (partial gs-update-feature db proj-fn))
     (flush-batch delete-batch (partial gs-delete-feature db))
 
-    (dosync (ref-set no-insert #{}))
+    (dosync (vreset! no-insert #{}))
     ))
 
 (defn- versions-in-batch [{:keys [dataset collection id]} batch]

        update-batch (volatile! (clojure.lang.PersistentQueue/EMPTY))
        delete-batch-size (or (:delete-batch-size config) (:batch-size config) 10000)
        delete-batch (volatile! (clojure.lang.PersistentQueue/EMPTY))
        no-insert (ref #{})
        ndims (or (:ndims config) 2)
        srid (or (:srid config) 28992)
        proj-fn (or (:proj-fn config) identity)

      (let [versions-in-insert (versions-in-batch feature @insert-batch)
            batched-delete-feature (batched delete-batch delete-batch-size flush-fn)]
        (dosync
          (vswap! no-insert #(clojure.set/union % (into #{} versions-in-insert))))
        (batched-delete-feature feature))))
  (proj/accept? [_ feature]
         (not (some #{(:collection feature)} no-visualization)))
